Vorarbeiten zur monographischen Darstellung von Wildpflanzensortimenten:Aegilops L.

Ohne Zusammenfassung

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Studies towards a monographic treatment of wild plant collections:Aegilops L.

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:Aegilops L.

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Diese Arbeit wurde im Zentralinstitut für Genetik und Kulturpflanzenforschung der Akademie der Wissenschaften der DDR, Querschnittsbereich Kulturpflanzenweltsortiment, angefertigt. Dem Direktor des Instituts, Herrn Prof. Dr. H.Böhme, danke ich für ausgezeichnete Arbeitsmöglichkeiten und vielseitige Unterstützungen. Dem Leiter des Querschnittsbereiches Kulturpflanzenweltsortiment, Herrn Dr.Chr. O.Lehmann, bin ich für zahlreiche Anregungen und die kritische Durchsicht des Manuskripts zu Dank verpflichtet. Der Mühe des Manuskriptstudiums haben sich außerdem Herr Dr. P.Hanelt und Herr Dipl.-Math. H.Knüpffer, der mir auch für den mathematischen Teil tatkräftig zur Seite stand, unterzogen. Ihnen gilt mein besonderer Dank. Die Kollegen der benach-barten Forschungsgruppe Taxonomie und Evolution haben durch Diskussionen und ihre inhaltsreiche Publikation (vgl.Fritsch et al. 1977) dazu beigetragen, mir die Attraktivität des Forschungsobjektes bewußt zu machen. Herr Dr. J.Kruse unterstützte mich sehr bei der Einarbeitung in die systematische Problematik der Gattung. Die Betreuung desAegilops- Sortimentes durch Herrn K.Köhler und seine Mitarbeiterin E.Gerloff erleichterte die Untersuchungen sehr. Meine bewährte Assistentin, FräuleinChr. Schmidt, war mir über ihr engeres Arbeitsgebiet hinaus oft in technischen Fragen eine unersetzliche Hilfe. Für die exakte Ausführung der Zeichnungen danke ich dem wissenschaftlichen Zeichner Herrn R.Pertack. Die fotografischen Aufnahmen wurden von Frau G.Terpe und Frau I.Kuntze ausgeführt. Allen, die weiterhin zur Fertigstellung der Arbeit beitrugen, möchte ich ebenfalls herzlich danken.     

Variation of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) and its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.)

The domestication of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) is briefly discussed. Using data documented as a matter of routine in genebank work, 63 accessions of cultivated flax from the flax germplasm collection of the Gatersleben Genebank are compared with 73 accessions of its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.), which have been observed in systematic field trials. Range of variation, genetically based variation, heritability and correlation of several characters are considered, especially with respect to the influence of domestication. Cultivated flax shows higher variation in the characters of generative plant parts, while pale flax varies more in the vegetative parts of the plant. The character correlations are similar in both subspecies. Of the 29 characters studied in pale flax the parameters describing tillering, height of plant, weight of seeds, width of petals and width of leaves are especially suitable for distinguishing between different accessions. In spite of the high heritabilities of most of the characters, the influence of the environment is significant in most cases.     

Genetic engineering of livestock

Genetic engineering of livestock is expected to have a major effect on the agricultural industry. However, accurate assessment of the consequences of transgene expression is impossible without multigenerational studies. A systematic study of the beneficial and adverse consequences of long-term elevations in the plasma levels of bovine growth hormone (bGH) was conducted on two lines of transgenic pigs. Two successive generations of pigs expressing the bGH gene showed significant improvements in both daily weight gain and feed efficiency and exhibited changes in carcass composition that included a marked reduction in subcutaneous fat. However, long-term elevation of bGH was generally detrimental to health: the pigs had a high incidence of gastric ulcers, arthritis, cardiomegaly, dermatitis, and renal disease. The ability to produce pigs exhibiting only the beneficial, growth-promoting effects of growth hormone by a transgenic approach may require better control of transgene expression, a different genetic background, or a modified husbandry regimen.     

Gonadotroph-specific expression of metallothionein fusion genes in pituitaries of transgenic mice

Transgenic mice expressing a metallothionein-somatostatin fusion gene contain high concentrations of somatostatin in the anterior pituitary gland, a tissue that does not normally produce somatostatin. Immunoreactive somatostatin within the anterior pituitaries was found exclusively within gonadotrophs. Similarly, a metallothionein-human growth-hormone fusion gene was also expressed selectively in gonadotrophs. It is proposed that sequences common to the two fusion genes are responsible for the gonadotroph-specific expression.     

Overexpression of low density lipoprotein (LDL) receptor eliminates LDL from plasma in transgenic mice

A complementary DNA encoding the human low density lipoprotein (LDL) receptor under control of the mouse metallothionein-I promoter was injected into fertilized mouse eggs, and a strain of mice expressing high levels of LDL receptors was established. After administration of cadmium, these mice cleared intravenously injected 125I-labeled LDL from blood eight to ten times more rapidly than did normal mice. The plasma concentrations of apoproteins B-100 and E, the two ligands for the LDL receptor, declined by more than 90 percent after cadmium treatment, but the concentration of another apoprotein, A-I, was unaffected. Therefore, overexpression of an endocytotic receptor can dramatically lower the ambient concentration of its ligand in vivo.     

Interpreting Soil Electrical Conductivity and Terrain Attribute Variability with Soil Surveys

Utilizing soil electrical conductivity (EC) measurements and terrain attributes for precision management will require secondary soil information for adequate interpretation. The objective of this study was to determine whether readily available second-order soil surveys were of adequate quality to aid with interpreting soil EC and terrain data. For three locations in Kentucky, USA, first-order soil surveys were created, second-order surveys reports were obtained, elevation was measured and used to calculate terrain attributes (slope, aspect, plan curvature, profile curvature), and bulk soil electrical conductivity was measured. Three analytical methods (an ordinary least squares analysis and two random field analyses), visual map assessment, and examination of least-squares means were used to assess the relationships between soil EC measurements, terrain attributes and first- and second-order soil surveys. The OLS and random field analyses were problematic. However, the ranking of the OLS F-statistics appeared to reflect the general relationship between landscape variables and first-order soil surveys. The landscape variables related particularly well with soil properties that had been impacted by past soil erosion. Unfortunately, however, second-order soil surveys in this study were not created at suitable scales to adequately interpret EC and terrain data regarding erosion history or other attributes. While these surveys may provide some useful information, field measurements, sampling, and observations will likely be required to develop high quality interpretations of soil EC and terrain attribute data.     

Diet-induced hypercholesterolemia in mice: prevention by overexpression of LDL receptors

The current studies were designed to determine whether chronic overexpression of low density lipoprotein (LDL) receptors in the liver would protect mice from the increase in plasma LDL-cholesterol that is induced by high-fat diets. A line of transgenic mice was studied that express the human LDL receptor gene in the liver under control of the transferrin promoter. When fed a diet containing cholesterol, saturated fat, and bile acids for 3 weeks, the transgenic mice, in contrast to normal mice, did not develop a detectable increase in plasma LDL. The current data indicate that unregulated overexpression of LDL receptors can protect against diet-induced hypercholesterolemia in mice.     

Simple sequence repeats marker polymorphism in emmer wheat (<Emphasis Type="Italic">Triticum dicoccon</Emphasis> Schrank): Analysis of genetic diversity and differentiation

Genetic diversity was investigated in 73 accessions of emmer wheat (Triticum dicoccon Schrank) from 11 geographical regions using a set of 29 simple-sequence repeat (SSR or microsatellite) markers, representing at least two markers for each chromosome. The SSR primers amplified a total of 357 different alleles with an average of 12.31 alleles per locus. The number of fragments detected by each primer ranged between 6 (Xgwm1066) and 21 (Xgwm268). Null alleles were detected in nine of the 29 primers used. A high level of gene diversity index was observed. Across the 29 primers, gene diversity ranged from 0.60 (Xgwm46) to 0.94 (Xgwm655), with a mean of 0.82. There was a highly significant correlation (r=0.882; p<0.01) between gene diversity index and the number of loci, showing the number of loci per se is a strong indicator of diversity. Analysis of genetic diversity within and among eleven geographical regions revealed most of the genetic diversity of the total sample resided within regions. The coefficient of gene differentiation (Gst = 0.27) showed that the genetic variation within and among the 11 geographical regions was 73 and 27%, respectively. High value of mean number of alleles per locus was found in Iran (4.86) followed by Morocco (4.10) and Armenia (4.03). On the contrary, lower mean number of alleles per locus was detected in Yemen (2.83). The average gene diversity index across regions ranged from 0.52 (Slovakia) to 0.67 (Morocco) with an average of 0.60. Multivariate techniques of principal component analysis and clustering were employed to examine genetic relationship among the 73 emmer wheat accessions vis-à-vis geographical regions of collections. The genetic distance coefficients for all possible 55 pairs of regional comparisons ranged from 0.63 (between Iran and Armenia, Georgia and Azerbaijan, Georgia and Slovakia) to 0.97 (between Morocco and Yemen, Spain and Georgia, and Turkey and Iran) with a mean of 0.82. From the PCA results, a two dimensional plot of PC1 versus PC2 was constructed. The scatter plot of the first two principal components which explained altogether 27% of the total variation depicted the presence of a clear pattern of geographical differentiation except in few cases like accessions from Caucasian region. Similar pattern of genetic relationships among accessions was observed in cluster analysis. The study provided genetic information of emmer wheat in relation to geographical regions of origin. The information could be utilized in crop improvement, germplasm conservation programs, and in further investigation.     

Vorschlag für einen Index der Allogamieneigung bei der Kulturgerste (Hordeum vulgare L. s. l.)

Zusammenfassung Die Fremdbefruchtungsrate bei Kulturgerste ist in der Regel sehr gering. Einige Anemophiliemerkmale sind aber gut ausgebildet, und unter besonderen Bedingungen kann das Ausmaß der Allogamie recht hoch sein. Aus den blütenbiologischen Merkmalen Antherenejektion (AE), Antherenlänge (AL), und Stigmatafläche (SF) wurden nach zwei verschiedenen Methoden Indices der Allogamieneigung (AN) kalkuliert, mit denen die potentielle Neigung der Gerste zur Allogamie geschätzt werden kann: AN=3,33 (AL·AE)+2,22 (SF·AE) und AN=–3,5+3,58 (AL·AE)+2,29 (SF·AE)Indices der Allogamieneigung werden für ausgewähltes Material des Gaterslebener Gerstensortiments angeführt (Tabellen 1 und 2).

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Proposal for an index of the tendency to allogamy in barley (Hordeum vulgare L. s. l.)

Summary Outcrossing in cultivated barley can be observed relatively seldom. There are some well developed characters of anemophily in barley, however, and under certain conditions a tendency to allogamy can be found. From the flower characters anther extrusion (AE), anther length (AL), and stigma size (SF) in two different manners the following indexes were calculated: AN=3,33 (AL·AE)+2,22 (SF·AE) and AN=–3,5+3,58 (AL·AE)+2,29 (SF·AE)By using these indexes it is possible to demostrate the actual tendency to allogamy in barley. Some results from the barley collection in Gatersleben are shown in tables 1 and 2.

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(Hordeum vulgare L. s. l.)

, , . , , , . , (), (AL) (SF), (AN), : AN=3,33 (AL · AE)+2,22 (SF·AE); AN=–3,5+3,58 (AL·AE)+2,29 (SF·AE); . (. 1 2).